Effect of graded levels of ethoxyquin in alfalfa leaf extracts on carotenoid and cholesterol concentrations in chicks

Alfalfa leaf extract treated with graded levels of ethoxyquin was incorporated into a casein diet at a level of about 50 g kg−1. The six leaf extracts contained 0, 956, 2435, 6777, 11 316, 25 150 mg kg−1 ethoxyquin and gave final concentrations of 0, 50, 125, 350, 600, and 1400 mg kg−1 in the diet, respectively. Each diet was supplemented with methionine, arginine and glycine and contained 120 g crude protein kg−1 and a similar level of energy. day old chicks were allocated to six treatments (n = 8) and fed the above experimental diets for 2 weeks. Dietary ethoxyquin up to 125 mg kg−1 improved body weight gain from 88 to 98 g and gain per feed from 0.44 to 0.46 although the differences were not significant. However, levels of ethoxyquin in the diet higher than 350 mg kg−1 significantly reduced both the body weight gain and gain per feed; these were 79 g and 0.41, respectively, in chicks fed the diet containing 1400 mg ethoxyquin kg−1. cholesterol level was significantly reduced from 209 with the control diet (containing 0 mg kg−1 ethoxyquin) to 157 mg dl−1 with the diet containing 50 mg kg−1 ethoxyquin. It was also lower with 125 mg kg−1 ethoxyquin than with the control diet, but higher levels of dietary ethoxyquin increased plasma cholesterol compared with that obtained with the control diet. noid concentration in the skin, liver and blood plasma were linearly reduced with the increase of ethoxyquin intake from 30.2, 75.0 and 38.4 μg g−1 at 0 mg intake to 19.2, 30.3 and 23.7 μg g−1 at 1400 mg ethoxyquin kg−1 diet, respectively.